Bosporus Straits, Turkey
Bosporus Straits, Turkey
| Topics: |  Oceans Geography Of Energy Energy |
The metropolis of Istanbul occupies both sides of the entrance to the narrow, 20-mile long Bosporus Strait connecting the Mediterranean and Sea of Marmara (south) to the Black Sea (north). This digital image was taken by the crew of the International Space Station on April 16, 2004. When this image was taken, strong currents carried turbid coastal waters from the Black Sea through the Strait and into the Sea of Marmara. The rugged uplands to the north of the city are forested and contain vital reservoirs. Source: NASA
Introduction
The Bosporus or Bosphorus (Turkish Boğaziçi or İstanbul Boğazı) is a strait ( that separates the European part (Rumeli) of Turkey from its Asian part (Anadolu), connecting the Sea of Marmara (Marmara Denizi) with the Black Sea (Karadeniz). It is an important oil transit chokepoint. It is 30 km long, with a maximum width of 3,700 meters at the northern entrance, and a minimum width of 750 meters between Anadoluhisarı and Rumelihisarı. The depth varies from 36 to 124 meters in midstream. It is a former river valley that was drowned by the sea at the end of the Tertiary period. The city of Istanbul straddles the Strait with a population of more than 11 million people.
Bosporus means in Greek "ox ford" or "ox passage"; the name comes from a Greek myth about Io's travels after Zeus turned her into an ox for her protection. The ancient Greeks referred to this strait as the Thracian Bosporus, as they called the Strait of Kerch the Cimmerian Bosporus. They also called a land area near these two straits by the same name: the Thracian Chersonesus, which is known today as Gallipoli, and the Cimmerian Chersonesus, known today as the Crimea. Due to the importance of the strait for the defense of Istanbul, the Ottoman sultans constructed a fortification on each side of it, Anadoluhisari (1393) and Rumelihisari (1451). Its strategic importance remains high: several international treaties have governed vessels using the waters. including the Montreux Convention Regarding the Regime of the Turkish Straits, signed in 1936. Some have argued that a massive flood occurring in the region around 5600 BC is the historic basis for the flood stories in the Epic of Gilgamesh and the Bible.
Oil transportation in the Straits
The Bosporus Straits are one of the world's busiest (50,000 vessels annually, including 5,500 oil tankers), and most difficult-to-navigate waterways. Some of the export routes for crude oil production from the Caspian Sea region pass westwards through the Black Sea and the Bosporus Straits en route to the Mediterranean Sea and world markets. The largest expansion of transit volumes would come from the expansion of the CPC oil pipeline. The ports of the Black Sea, along with those in the Baltic Sea, were the primary oil export routes of the former Soviet Union, and the Black Sea remains the largest outlet for Russian oil exports. Exports through the Bosporus Straits have grown since the breakup of the Soviet Union in 1991, and there is growing concern that projected Caspian Sea export volumes exceed the ability of the Bosporus Straits to accommodate the tanker traffic. Turkey is concerned that the projected increase in large oil tankers would pose a serious navigational safety and environmental threats to the Bosporus Straits. The largest oil tankers that can pass through the Bosporus Straits are the Suezmax class tankers (120,000-200,000 dead weight tons).
Oil tankers in the Bosporous Straits.
Under the Montreux Convention of 1936, commercial shipping has the right of free passage through the Straits in peacetime, although Turkey claims the right to impose regulations for safety and environmental purposes. In October 2002, Turkey placed new restrictions on oil tanker transit through the Bosporus that have slowed tanker transit, including a ban on nighttime transit for ships longer than 200 meters, effectively including all crude oil and large petroleum product tankers. Poor weather has caused transit delays as well; during the past winter, delays reportedly reached as much as 20 days for oil tankers waiting to transit the Straits, costing about $50,000 in demurrage charges per day.
Marine pollution concerns
Increased shipping traffic through the narrow Bosporus Straits has heightened fears of a major accident that could have serious environmental consequences and endanger the health of the 12 million residents of Istanbul that live on either side of the Straits. The Straits have witnessed an increase in shipping traffic since the end of the Cold War to the point that around 50,000 vessels per year (nearly one every 10 minutes) now pass through them. Around one-tenth of these are crude oil or liquefied natural gas tankers. This increased congestion has led to a growing number of accidents; between 1988 and 1992, there were 155 collisions in the Straits. In January 2001, work began on building a comprehensive radar and vessel control system for the waterway.
With the high volume of oil being shipped through the Bosporus, oil tanker accidents can release large quantities of oil into the marine environment. This danger was underscored in March 1994, when the Greek Cypriot tanker Nassia collided with another ship, killing 30 seamen and spilling 20,000 tons of oil into the Straits. The resulting oil slick turned the waters of the Bosporus into a raging inferno for five days, but because the accident occurred in the Straits a few miles north of the city, a potential urban disaster was averted.
In the aftermath of the 1994 Nassia disaster, Turkey passed regulations requiring ships carrying hazardous materials to report to the Turkish environmental protection ministry. However, Turkey's power to regulate commercial shipping through the Straits is limited by the 1936 Treaty of Montreux that delineates the Straits as an international waterway. Although subsequent international agreements have given Turkey the right to regulate the right of passage through the Straits to ensure a steady and safe flow of traffic, due to pressure from some Black Sea border countries, Turkey has not been stringently enforcing the shipping laws passed in 1994. Thus, only a small number of vessels passing through the Straits report their cargo. In July 2001, Turkey's environment minister, Fevzi Aytekin, stated that he would use all legal tools at his disposal to stop Russian nuclear waste from being shipped through the Bosporus.
As the number of ships through the Straits grows, the risk of accidents increases, and traffic will likely increase as the six countries surrounding the Black Sea develop economically. With tonnage on the rise as well, the threat of collision is not the only danger: on December 29, 1999, the Volgoneft-248, a 25-year old Russian tanker, ran aground and split in two in close proximity to the southwest shores of Istanbul. More than 800 tons of the 4,300 tons of fuel-oil on board spilled into the Marmara Sea, covering the coast of Marmara with fuel-oil and affecting about 5 square miles of the sea.
In addition, while major spills can bring about immediate environmental consequences, the presence of large oil- and gas-carrying ships in the Straits causes other problems, such as the day to day release of contaminated water as the ships ballast their holds. Pollution in the Straits contributed to a decline in fishing levels to 1/60th their former levels.
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Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Energy Information Administration. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Energy Information Administration should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content. |
Citation
Steve Baum (Contributing Author);Eia (Content Source);Cutler Cleveland (Topic Editor) "Bosporus Straits, Turkey". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth April 17, 2010; Last revised Date October 25, 2011; Retrieved February 9, 2012 <http://www.eoearth.org/article/Bosporus_Straits%2C_Turkey>
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Comments
Posted by john Wilson on November 16, 2010 6:28 pm
Good Info, If it is high risk to pass the Bosporus. International Shipping Companies should go up to marmara sea and pass the Black sea via Land
Posted by Peter Boyce on November 21, 2010 11:55 am
The caption of the photo is quite misleading to mention the Mediterranean! The Bosporus is the strait connecting the Black Sea to the Sea of Marmara as the article text rightly says. Adding the Mediterranean includes the Dardenelles.